Few people think about if after flushing the toilet each morning, but the processing and disposal of human waste is actually a $100 billion business.

Beyond supporting entire industries, it can leave a hole in many people’sbudgets, too. Consider this: on average, the parents of a newborn can expect to change 6,000 diapers during the first two years. During that time, they’ll spend about $1,600 on diapers, not to mention the added costs of wipes and diaper rash ointments.